I'm running a somewhat modified version of the Lost Mine of Phandelver adventure.
I was DMing my second ever session, and decided to roll on the lingering injuries chart. I got a 3 and told the player, whose character was nearly killed by a group of orcs then and there, that they chopped off his leg and left him there. He made his death saves and stabilized, and another player character dragged him away to keep him safe.
I was not planning on the roll ending up being one to completely cut off his leg - but that's unimportant, as it's happened already, and I don't want to retcon it if I can help it.
I'm looking for a way he can regrow/regenerate his leg but I'm not sure how to go about it. It could be replaced with Regenerate but that is a 7th-level spell; I'm not sure how I should go about helping him to replace it, as the players are only 3rd level.
It's not important that the character necessarily recover immediately. I'm looking for options for how to go about this, as I'm new to all of this and want to do right.
In case it's relevant our party composition is a Variant (Winged) Tiefling Warlock of the Fiend and an Aarakocra Monk.